The difference in healthcare cost is $220/month, or about $7 per day. Free lunch could easily be worth that much. More importantly though, the free lunch offering has a $20k higher salary.
My experience as a Brit working in the US is also that health insurance with higher employee contribution is often also (bizarrely) more expensive and worse quality in other ways, so there are additional non-financial (or not just financial) factors to consider. But the OP hasn't given enough detail to evaluate.